Pneumatic check for elevator-gates



Patented Mar. 2|, I899:

F. P. HINDS. PNEUMATIC CHECK FOR ELEVATOR GATES.- (Application filed oc.20, 1897.) (No Model.)

V?) W I NITED STATES PATENT rrrcn.

FRANKLIN P. HINDS, OF BOSTON, 'MASSACHUSETTS, ASSIGNOR TO JOHN F.

' BERTON, OF SOMERVILLE, MASSACHUSETTS.

I PNEUM ATIC CHECK FOR ELEVATOR-GATES.

SPECIFICATION forming part of Letters Patlit N0. 621,669, dated March21, 1899 A li ti filed October 20, 1897. Serial No. 655,789. (No model.)

To aZZ whom it may concern:

Be it known that I, FRANKLIN P. HINDS, of Boston, in the county ofSuffolk and State of Massachusetts, have invented a new and usefulImprovement in Mechanism for Regulating the Fall of OounterweightedElevator- Gates, which will, in connection with the accompanyingdrawings, be hereinafter fully described, and specifically defined inthe appended claim.

My present invention relates to mechanism for controlling the descent ofa gate or barrier suspended by a counterweighted cord attached to themiddle of thegate and passed over and sustained by one or moreoverhanging pulleys .in the usual manner, the gates being guided by sidegrooves running in cor-.

responding bars vertically secured to the sides of the passage-way ordoorway to the well and being what is known as a half-automaticgate-that is, one raised by hand to open the passage-way to the well andcar and locked v in such raised position while the car stands at thedoor, but is automatically released by the movement of the car in eitherdirection away from the door and then falls by gravity, thecounterweight serving to restrain it somewhat and to help in raising it.The counterweight, however, is not sufficient to counterbalance the gateand thereforecannot prevent its falling with increasing velocity andconsequent liability to injure itself or any articles or persons caughtin its path. I

- therefore employ an auxiliary controller consisting of an adjustableautomatic check, which is hereinafter more fully described and forms themost essential feature of my present invention. f

In the drawings, Figure 1' is a front elevation of an elevator-gate anddoorway leading to the well, the gate being closed down and mycontrolling devices being shown in place above the gate. Fig. 2 is aside view of the controlling device detached from its support on thewall of the elevator-well. Fig. 3 is an end view of the same as seenfrom the right of Fig. 2. Fig. 4 is a longitudinal section takenvertically through the center of Fig. 2. Fig. 5 is a perspective View ofthe inner faces of the two halves of the pulley over which thecounterweight cord or chain passes to the gate and shows theconstruction and arrangement of the ratchet devices within the pulley.Fig. 6 is a side view of a modification in which the cylinder is pivotedto the hanger so as to oscillate thereon and the ratchet-shaft of thep-ulley is connected-directly with the piston-rod which operates theair-pump.

Referring to the drawings, the gate A is sustained by a chain or cord B,passed over a grooved pulley 0, made in two parts and which is attachedto a hanger D, secured to the wall. ratchet-shaft E, journaled inbearings F in said hanger and arranged to turn freely in one directionon the shaft E, which also revolves in said bearings. The pulley 0carries between its two halves a ratchet-pawl G, which is arranged toengage the-notches or cuts H in the ratchet-shaft E when the pulley ismoved thereon in the direction indicated by the arrow; but when theratchet-pulley O is rotated'in the opposite direction the pawl G doesnot engage the notches H. Consequently the pulley rotates freely in thatdi rection, thus facilitating the raising of the gate by hand; but whenthe gate is released, as before stated, and starts by its gravity todescend it causes pulley G to rotate in the opposite direction, when thepawl G, actuated by a spring, as shown, engages one of the notches H onshaft E, and thereby causes the shaft to rotate with it. The shaftcarries an arm I, which connects with a link J,

which operates a piston-rod K, secured to a piston-head N in a cylinderL. These lastnamed devices constitute the auxiliary controller beforereferred to and are a part of or properly secured to the body of hangerD, as shown. The cylinder L has two adjustable vents M M, between whichthe double piston-head N, carrying leather disks closely fitted to theinterior of the cylinder, moves back and forth, such reciprocation beingagainst pneumatic resistance in both directions, and the rotation ofshaft E and pul- The pulley O is mounted upon a ley 0 when the gate isfalling is thereby checked, and a toorapid descent of the gate is thusprevented, the controller being capable of adjustment by means of ventsM and M, thereby producing more or less pneumatic resistance. Thedownward speed of the gate can be nicely regulated and adapted to gatesof varying sizes and weights. By this device I overcome the commondifficulty with such gates which arises from the fact that if too nearlycounterbalanced by the weight they are apt under varying conditions ofthe atmosphere as to dampness and dryness to stick and not fall andguard the doorway at all or to become too free and go down with damagingforce, and I have found it impos sible to adjust such gates by a simplecounterweight so as to effect a uniform and proper movement of the gateand certainty of its antomatic operation; but with the describedpneumatic attachment or air-pump, which is nicely adjustable andpractically uniform in its action, I can give such preponderance to thegate over the counterweight as to insure its descent under allatmospheric conditions and at the'same time so adj ustthepneumaticcontroller as to nicely regulate the descent of the gate and avoid allundue speed thereof and all damaging force and shock when such movementis arrested.

It is obvious that the invention described is applicable to other formsof gates or barriers and counterweighted drop scenes or curtains toautomatically regulate their fall.

In the modification shown in Fig. 6 the cylinder L is pivoted to thehanger at L, so as to oscillate thereon, and the arm E of theratchet-shaft is attached directly to the piston.

The piston-head is retarded in its moveance whatever to the raising ofthe gate,owin g to the ratchet-pulley over which the cord passes. a

I claim- The combination with a vertically-movable gate or barrier, of acounterweight therefor and a flexible connection between the two, apulley for said connection and mounted on a shaft and adapted to rotatefreely on the shaft when the gate is elevated and to cause the rotationof said shaft when the gate is descending, and a cylinder and piston,the latter having a pitman-and-crank connection with the shaft of saidpulley.

Boston, Massachusetts, September 18, 1897.

FRANKLIN P. IIINDS. Witnesses:

EUGENE HUMPHREY, R W. E. HOPPER.

